Railway-train-controlling system.



I. c. McDONALD. RAILWAY TRAIN CONTROLLING SYSTEM." APPLICATION FILED DEC. 10. I9I2- RENEWED IAN. 21. 1915. 1,151,026. I Patented Aug. 24, 1915.

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1,0 McDONAL D. RAILWAY TRAIN CONTROLLING SYSTEM. APPLICATION FILED DEC-l0, l9l2- RENEWED IAN. 2|, I915- 1,151,026. Patented Aug. 24, 1915.

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RAILWAY-TRAIN-COIITROLLING- SYSTEM.

Specification of Letters Patent.

hpplication filed December 10, 1912, Serial in. 736,011. Renewed January 21, 1915. Serial No. 3,630

To all whom it may concern Beit known that I, JOHN C. MoDonALn, a citizen of the United States, and a resident of New York, in the county of New 1 York and State of New York, have lnve'nte d certain new and useful Improvements in Railway Train Controlling Systems, of

.which the following is a specification.

power is cut ofi from a motor car or train' seeking to enter a block already occupied,

also means whereby sections of a power conductor whlch are not at the moment required to be energized are grounded until required to be energized, also means for guarding trains which may, by accident or otherwise, drift beyond sections of the block in which they should come to rest.

Other features of my invention will 'be pointed out hereafter.

The objects of my invention are'to facilitate the, operation of railways, particularly electric railways, to reduce the danger of collisions, to provide simple means for grounding power conductors which are not at the moment required to be energized, to provide simple means .for protecting trains which may drift beyond sections in which they should come to rest, and generally to make the circuits and apparatus of the system simple andreliable and to cause such circuits and apparatus to afford ample protection to trains.

The invention herein described comprises the system, circuits and apparatus of my application filed October 9, 1911, Sr. No. 653,477, with certain additions and modifications, as hereinafter pointed out.

I will now proceed to describe my invention with reference to the accompanying drawings, and will then point out the novel features in claims.

. In said drawings: Figure 1 is a diagrammatic view showing the circuits and switches of one track of a double track electric railway system embodying my invention, the direction of normal progress along such track being indicated by anarrow. Fig. 2 is a side view and Fig. 3 an end view of one of a smallerscale, a longitudinal section of a two'compartment switch, such asindicated in Fig. 1, and'Fig. 8 is a transverse section of the two compartments of such switch, indicating the arrangement of contact points therein. Fig. 9 is a diagrammatic view illustrating the application of my invention to.

the control of trains propelled by means other than electric power drive from a power conductor located along the track.

According to my invention, as preferably applied to electric railways, current is com; "munlcated to the motors of a car or tram on ing as many sections as there are. blocks:

which conductor may conveniently be a .third rail, though it might also bea trolley wire. To each section of such conductor current is communicated from a feedwire through'a suitable switch controlled by track circuits; to which end one of the track rails is divided into as manyinsulated sections as there are blocks, the other rail (which'is a (grounder return rail) not being so divi ed.

' The switches which I prefer to employ. are mercurial switches operated by clectromagnets, each such magnet being controlled by mm of the track circuits. 1

Referring first to Fig. 1, T designates the track rail which is not divided into block sections, and T T etc., designate block sections of the'other track rail. R R", etc.

designate corresponding sections of the current supply conductor. Current is supplied to the various power rail sections R R R etc., through a feed conductor F, and through switchesS S etc., and conductor 17, there being one such switchfor each block. lVithout' limiting myself to any particular variety of switch I will state that I prefer a mercurial contact switch of the conand comprising anoscillatory barrel 1, constructed to contain mercury or-other suitable fiuidconductor, and pivoted on an axis 2 somewhat above the geometric center of the drum 1. The switch further comprises an struction'i-llustrated in Figs. 2-6 inclusive,

" cuit of the switch magnet 4 of'each' block is controlled by the track circuit ofthat block,

magnet 4, an armature 5, for moving the barrel in one direction (the vmagnet and armature illustrated being of solenoid. and plunger type) and a retractile spring 6. The barrel 1 is customarily provided internally with a layer of mercury 7, of suitable depth, and to keep the surface of this mercury clean, and also to reduce evaporation, and prevent sparking, the surface 9f the mercury may be covered'with a'layer 8, of oil or the like, of suitable depth; such oil being a good insulator.' The barrel 1 is further provided with two sets of contact points, one set being numbered 9 and 10, the other set being numbered 11 and 12. It will be understood that the drum 1 is constructed of somejnon-conducting material, sothat the contact pieces 9-12 inclusive are .insulated from each other, except as they dip into the. mercury, or that other suitable meansare employed to insulate the contact pieces one from'another.v The location of the various contact pieces is such that con tacts 9 and 10 are immersed in the mercury when the switch barrel 1 is in its normal-p0 sition ,the contacts 11' and 12'being then out of mercury; and .that when the switch barrel isin its abnormal position, produced by energization of the magnet 4, contacts 11 and 12 will be immersedin the mercury, and contacts 9 a'n d 1 0,will be out of the mercury and therefore insulated from one another. I p

Re'ferring now again to Fig. .1, and considering. the circuits of the system. The cirand also by the contact. points of a switch of. one of the blocks beyond. Customa'rily it is considered sufiicient to maintaina-train interval'of not morethan two blocks, be-H tweentrains, and' therefore in Fig-v 1 I have shown the''circuit of. each switchmagnet 4 controlled by the contact points 9 and 10 of a switch two blocks ahead; but it will be obvious that the circuit of each switch magnet 4 might be'controlled by the contacts of corresponding switcheseither a less number of bcllocks or a greater number of blocks ahea Considering-now the switch-operating circuitfof one of the blocks, block T for ex-' switchoperating generator '16, diagrammatically represented. in the drawing as a battery, the'otlu r pole of which is grounded.

Rail T being ground edit will be apparent that when a car or train'cntcrs block T the wheels of such car or train will complete the track circuit from T to T thereby completing a circuit from the grounded side of generator 16, through rail T, the wheels and v axles of the train, the rail T the magnet 4 of switch S to contact 10 of switch S (neglecting for themome'nt switch U If' tecting thetrain from other trains inrear,-I

as will be described presently, and also con necting rail R to feed wire F. -Supposing,'

however, that the block T is occupied when a trainenters block T In such case, since the track circuit of block T passing through magnet 4 of switch S of that block T is completed through the; wheels and axles of the car or train of theblock T the switch S will be in its abnormal or operating position when the second train seeks to enter block T and therefore the barrel of switch 8- will be in its abnor? mal position, contacts '9 and 10 of switch S" fwill be insulated from one. another, and contacts 11 and 12 of switchS will be connected through-the .mercury of switch S The function of these-contacts 11 and 12 will be described presently. Since', with block T occupied, the train entering block T .can-,

not complete the circuit through the magnet 4 of switcihS, because such circuit is brokenat contact 9 and 10 of switch. 8?, it follows that the train entering block T can receive no current from power conductor section B, and therefore the train entering block T} 'must (except in exceptional-instances as de scribed hereinafter) come to .rest shortly after entering that block, and must remain at rest until block T? is no longer occupied. As soon as the car or train on the block T passes out of that block. the barrel of switch S will return to normal position by gravity, and thereupon the track circuit of'magnet 4 of switch S of block T will be-completed through contacts 9 and 10 of switch S and the train in block T may proceed.

The sections R R etc., of the power rail overlap somewhat the corresponding sec-.

tions T ,'T-, of the sectional track rail.

\Vith the sectional power conductor system above described, I preferably-combine a signal system, the circuits of which are controlled by the same switches which control the power circuits. The contacts 11 and 12 of each switch are signal-circuit contacts. Consideringthe signal circuits of the block T it will be seenthat when contacts 11 and 12 of switch are connected through the mercury of that I, switch, not only is the power circuit complete from feed wire F to contacts 12 and 11, of switch S and wire 17 to power conductor section R but also a signal circuit iscon plete, from feed wire F through contacts 12 and 11, and signal wire 18 to a danger signal D of the preceding block and to caution signal C of block T These dangennntlca-ution signals may be of any suitable construction; but I have dicated electric lamps for the purpose. As is customary in ordinary railway work, where lamps or the like are used for signals, the danger signal lamps will be of one color and the caution signal lamps will be of another color. In the drawings I have indicated the danger signal lamps" by the symbol O and the caution signal lamps by the symbol (3. It will be seen thereforethat when a car or train seeks to enter a block, R for example, when the second block ahead is occupied, the motorn an will find the cantion lamps of the block which he is seeking to enter, lighted, and will thereby be notified to bring his train to rest before entering the dead rail section R Should the train in block T 3 leave that block by backing into block T then as soon as such train enters block T and before it has left block T it will actuate switch S and thereby Will illuminate the danger signal lamps D of block T so that notwithstanding when such train of the block T has passed entirely from block T 3 to T and so has permitted operation of switch S the train seeking to enter block T will be debarr ed from preceding on in that block, by the danger signal D.

So far as described, the system and circuits (except as to'the switches U U U", etc, which up to this point have. been neglected) are the same as that of my said prior application Sr. No. 653,177. For each block there is, in addition to the main switch S, or. S or S etc, an additional switch, U or U or U, etc., oi similar construction to the switch S or S or S*, etc., except that these switches U, UKU etc, are double switches, and except that they are provided with contact points on' one side of the barrel only. These switches U U U, etc, are operated by magnets 19 bridged across from conductor 17 to return conductor l-t; so that when a magnet -iof one of the switches S ispartments. 21 and each compartment 21 having two contact pieces 2 and 21, which are connected electrically by the mercury in that compartment 21 when the switch is in normal position, each compartment 2'2 havmg two brushes and 26, wh-ich are conthrough theswitch magnet 4 of thatsecond, block'in rear, to the contact piece 10 of the. I block at which is located the particular The contact i switch U under consideration. piece :26 of each switch U is connected to the circuit 1718 of the block at which that particular switch U is located, and the corresponding contact piece is connected to ground, these contact pieces 25 and 26 therefore serving to connect to ground the insulated power conductor section R or R or R, etc, of that particular .block. These switches U havetwo functions, the first of which is as follows: Suppose that a train is stalled on section T for example. The switch S is then in abnormal position, preventing a train which may enter block T from receiving current in case it. reaches power conductor R. This train entering block T 3 should come to rest before it leaves block T altogether; but suppose this train position through a train being on block T the signal D of block T and the signal C of block T are stillat safety, and switch S might be operated by a train now entering block T (except for the action of switch U ,lVhile the train on block T 5 prevents switch S from going to abnormal position when the second train enters block T, it

does'not prevent the switch U from going:

to abnormal position, so that promptly upon the entry or a train in the block T, when block T -is occupied, the magnet 19bit switch U is energized through completion of the circuit from rail T through conductor 13 to magnet 19 of switch U, and thence to conductor ll and through conductor 15 and generator 16 back to ground, and. contact pieces 23 and 2% of switch U then break the circuit of magnet of switch S so preventing the. operation of switch S, in case a train should enter the block. And the switch U in like manner protects the rear of the train entering block T. In like manner, if a train is stalled on any switch or block, and one oi the signal. wires is broken, the switch S of the block two blocks in rear might be operated by a train entering that block two blocks in rear, so, except for: the action of the switch U of the block in which the train ahead is at the moment, allowing such rear train to proceed. into the block responding conductor 17 and the corre-' sponding conductor 18 to the contact piece 26 of the corresponding switch U and thence through the mercury of that switch to the corresponding contact piece 25 and thence to ground. This ground connection is broken by the operation of the switch U as soon as.

the corresponding block is entered by a train; and when the train passes out of that block, the switch U, returning to normal, reestablishes the ground connection. Such ground connection renders idle sections of the power rail inert and harmless, except when required to be energized by the presence of a train on the corresponding block, and also discharges each section of the power rail immediately the train passes from the corresponding block.

In the following claims, the switches S S etc., are termed primary switches, and the switches U U etc, are termed secondary switches.

The train controlling system herein illustrated and described is applicable to the control of trains propelled by means other than electrical power, derived from a power conductor located along the track. This is illustrated in Fig. 9, in which P designates a sectional controlling circuit rail, corresponding in all respects to the sectional )ower-rail R of Fig. 1, except that this rail is'not employed for the supply of propulsion current, but is merely employed for the supply'of current to operate a magnet Q, on the locomotive or car; this magnet Q controlling an air brake valve 27 or a powersupply valve '28, or both, in such manner that when the magnet is energized the air brake valve is closed and the power controlling valve is open. The locomotive or other car upon which this electrieally-controlled valve mechanism is mounted, is provided with a suitable contact shoe 29 making contact with the rail P; and a circuit conductor 30 leads from this shoe to the magnet Q and thence is grounded to the frame of the car or locomotive. The supply of current to the sections ,of the rail P is controlled in precisely the same manner as is the supply of current to the sections of the rail R controlled, in Fig. 1. It follows therefore that so long as any section of the rail .1 with which the shoe 29 may be in (iontact at any moment, is energized, the train may proceed; but when this section is denergized, by the action of one of the switches S or U,

the brakes will beapplied, and the power.

cut ofi and the train brought to rest.

\Vhat I claim is 1. A railway traimcontrolling system comprising in combination a power conductor divided into sections, means foi' supplying current to the several sections of said conductor, ,comprising a primary electrically-controlled switch for each'such section, a secondary electrically controlled switch for each such section, and track circuits including means for operating said switches, the track circuit for each such primary switch passing through contacts of both the primary and secondary switches of a section in advance, which contacts are closed when such primary and secondary advance switches are in clear position, and are broken when such primary and secondary advance switches are in danger position, the

. track circuit of'the secondary switch of each such section being free from such control by an advance switch; whereby each secondary switch is caused to occupy the danger position when a train is operating its track circuit independent of the operation or non operation of the corresponding primary switch.

2. A railway train-controlling system comprising in combination a power conductor divided into sections, means for supplying current to the several sections of said conductor, comprising a primary electrically-controlled switch for 'each such section, a secondary electrically controlled switch for each section, and track circuits including means for operating said switches, the track circuit for each such primary switch passing through contacts of both the primary and secondary switches of a section in advance, which contacts are closed when such primary and secondary advance switches are in clear position, andtare broken wvhen such primary and secondary advance stvitches are in danger position, the track ciriiuit of the secondary switch of each such section being free. from such control by .an advance switch; whereby each secondary switch is caused to occupy the danger position when a train is operating its track circuit, independent of the operation or non-operation of the corresponding primary switch, one of said switches of each such section comprising means for grounding the'corresponding section when such switch is; in clear posi tion. I

3. A railway train-controlling system comprising in combination a power conductor divided into sections, means for supplying current to the several sections of said conductor, comprising a primary electrically-controlled switch for such section,

a secondary electrically controlled switch for each such section, and circuits including means for operating such switches, arranged to be operated by trains, the circuit for each such primary switch passing through conacts of both the primary and the secondary switch of a section in advance, which contacts are closed when such advance switches are in clear position, and are broken when such advance switches are in danger position, the controlling circuit of each such secondary switch being free from such control by an advance switch, whereby each secondary switch is caused to occupy the danger position when a train is operating its controlling circuit independent of the operation or non-operation of the corresponding primary switch.

4:. A railway train-controlling system comprising in combination a power conductor divided into sections, means for supplying current to the several sections of said conductor, comprising a primary electrically-controlled switch for each such section, a secondary electrically controlled switch for each such section, and circuits comprising by an advance switch, whereby each secondary switch is caused to occupy the danger position whena train is operating its controlling circuit independent of theoperatio'n or non-operation of the corresponding primary switch, one of said switches oi each such section comprising means for ground a ing the corresponding section when such switch is 1n clear position.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JOHN C. MCDONALD. Witnesses:

PAUL H. FRANKE, D. A. DAVIES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

